METCALF: HOMOPTERA AUCHENORHYNCHA 533 



We hear on all sides complaints about the rapidly changing nomenclature, 

 and the International Commission is engaged apparently in an attempt to sta- 

 bilize our nomenclature by decrees fixing certain names. How futile this is can 

 be appreciated from a number of apparent facts. First, it is doubtful whether 

 we know more than a third of the genera and species of the Homoptera Aucheno- 

 rhyncha now living in the world. Second, until recently we have had no com- 

 prehensive bibliography of this group. Third, only about a fifth of the families 

 have been covered with an up-to-date catalogue of the genera and species. It 

 might be remarked in passing that although I spend a considerable portion of 

 my time on the current literature, I can just barely keep pace with it. Yet I am 

 foolhardy enough to believe that any attempt to fix names is going to fail utterly; 

 first, because there are not enough workers to study all of the literature of the 

 past and to fix names with accuracy, and second, because the names that are 

 fixed are bound to change with our increased knowledge of the real taxonomy 

 of the group. 



The changes in nomenclature in systematic zoology are no more drastic than 

 the changes in the nomenclature of any other science, biological or physical, 

 which is developing rapidly. There is something amusing, if not ridiculous, in 

 reading biological papers and noting how carefully the writer has checked every 

 factor involved except the accepted nomenclature of the day. 



If evolution is an explanation of the facts of the biological world, then the 

 center of origin theory must be accepted. That is, there must be for each species 

 and each genus a center on the earth's surface where these units of the animal 

 kingdom have arisen. It follows, therefore, that a clear understanding of the 

 zoogeography of the animals of a group is a necessary prerequisite to an under- 

 standing of the taxonomy, ecology, phylogeny, and other areas of the field of 

 biology. A great deal of progress has been made in the study of the zoogeography 

 of the Homoptera. Of course, much more than has already been discovered 

 awaits the inquiring mind of the future student. Most of the facts of zoogeog- 

 raphy are so patent that they would seem to need little argument for their sup- 

 port. Except where nature has been interfered with by man and his commerce, 

 we would naturally expect that species would spread from their center of origin 

 gradually, perhaps more rapidly than we think, to other areas to which they 

 can adapt themselves. A firm foundation for our study of zoogeography was 

 established by many different workers working on local lists of the countries of 

 Europe, the states in the United States, South Africa, India, Japan, Australia, 

 various countries in South America, and other regions. 



The real purpose of a short history such as this is to call attention to the 

 great areas of study which await the nimble fingers and keen minds of future 

 research workers. For these alone can develop the techniques which will push 

 forward the frontiers of our knowledge of one of the larger orders of the insect 

 kingdom and one which contains some of the most bizarre animals known to man. 



